The invention relates to a method and a device for operating a motor vehicle, wherein with the method and/or the device, respectively, the power consumption of an electrical consumer of the motor vehicle is controlled.
Owing to the growing awareness of the environment, a lower energy consumption is becoming more and more important to users of motor vehicles. Hence, one important aspect is an efficient energy usage.
DE 102 11 970 A1 discloses a method for adjusting the power demand of a plurality of electrical consumers (loads) in the electrical distribution systems of motor vehicles. In order to control the power consumption of a plurality of consumers, each of these consumers is constantly provided with information about the total electrical power that is available at any given time.
Hence, the object of the present invention is to provide a method and a device for operating a motor vehicle, wherein the method and/or the device, respectively, support an efficient use of energy.
This and other objects are achieved by a method and a corresponding device for operating a motor vehicle, in which at least one weighting value is determined in a manner that is influenced by a vehicle user. A maximum released power, which a predefined electrical consumer of the motor vehicle may consume, is determined as a function of the weighting value. The power consumption of the electrical consumer is controlled as a function of the maximum power that is released.
This strategy makes it possible for a vehicle user to influence the power consumption of one or more electrical consumers; and at the same time, in particular, the needs of the vehicle user can be taken into consideration. This feature can contribute in an advantageous way to the goal of a more efficient use of the energy in the motor vehicle.
The vehicle user can influence specific properties of the motor vehicle by use of the weighting value. The weighting value can be, for example, representative of a comfort property of the motor vehicle, a high performance driving style and/or a cruising range of the motor vehicle. Given a predefined set of electrical consumers of the motor vehicle, a specific consumer can be classified, as a function of the weighting value(s), as more or less important in its significance to the vehicle user. A small weighting value, which is representative of, for example, the comfort property of the motor vehicle, has, for example, the result that, for example, less power is made available to the seat heating system and/or an air conditioning system, as compared to a case, in which the weighting value has a higher value.
The power consumption of the electrical consumer can be controlled by way of a control unit, which is disposed in the motor vehicle and which controls the power consumption of each consumer in such a way that the power consumed by the electrical consumer does not exceed the determined maximum power that is released to the consumer for its consumption. As an alternative or in addition, it is possible that the electrical consumer is designed to set its power consumption, as a function of the maximum power that is released for the electrical consumer.
According to one advantageous embodiment, the weighting value is determined as a function of an input of the vehicle user. This arrangement has the advantage that those needs that are specific to the vehicle user can be taken into consideration. An input can be performed by way of an input unit that is configured in such a way that it lends itself, for example, to use with a keypad, which is arranged in the vehicle; and/or an input can be performed by use of a sensor screen. It is possible, for example, to enter a numerical value from a predefined range of values by use of a keypad for the respective weighting value; and/or, for example, values are predefined by touching the sensor screen. For example, a predefined position of the sensor screen is assigned a vector of weighting values; and the dimension of the vector is equal to a predefined number of weighting values. It is also possible that one or more predefined standard weighting(s) is or are proposed to the vehicle user; and that the vehicle driver selects one of the proposed standard weightings.
According to another advantageous embodiment, the weighting value is determined, as a function of at least one operating variable, by way of a performance monitor. The operating variable can be representative of a measured variable that is collected; and/or the operating variable can be representative of a derived variable. The operating variable can be, for example, representative of a user profile of at least one electrical consumer; and this user profile is specific to a vehicle user; and/or the operating variable can be representative of a driving style of a vehicle driver. This feature constitutes an advantageous approach that enables the needs of a vehicle user to be considered in an indirect way in the course of determining the weighting value(s).
According to an additional advantageous embodiment, an allocation value for the electrical consumer is determined as a function of the weighting value; and the maximum released power, which the consumer may consume, is determined as a function of the allocation value. This feature makes it possible to determine in a simple way the maximum power that is released; and this feature also makes it possible to control in a simple way the power consumption of the electrical consumer. The allocation value can represent a fixed percentage, so that, for example, a fixed percentage of 60%, of the electrical consumer's maximum power or nominal power, desired power is made available to the electrical consumer as the maximum power released for it.
According to another advantageous embodiment, a functional variable is determined as a function of the weighting value; and the maximum released power, which the electrical consumer may consume, is determined as a function of the predefined allocation function and the determined functional variable for the electrical consumer.
According to an additional advantageous embodiment, the maximum released power is determined as a function of the total electric energy that is available for the predefined electrical consumers of the motor vehicle.
According to another advantageous embodiment, the functional variable is representative of a sum of a normalized functional variable and a setting value, wherein the setting value is determined as a function of the weighting value.
According to an additional advantageous embodiment, the functional variable is representative of the product of a normalized functional variable and a setting value.
According to an additional advantageous embodiment, the allocation function is represented by the following equation:f(x)=1−(1−x)z 
where
x: normalized energy availability
f(x): normalized maximum power that is released
z: functional variable
The allocation function makes it possible to consider both an energy availability and also the weighting value in the course of determining the maximum power that is released for an electrical consumer.
According to another advantageous embodiment, the maximum released power, which the electrical consumer of the motor vehicle may consume, is optimized in consideration of at least one quality function and as a function of the weighting value; and the power consumption of the electrical consumer is controlled as a function of the optimized maximum power that is released.
According to an additional advantageous embodiment, the limited functionality of the electrical consumer is determined and signaled by use of visual cues, auditory cues and/or tactile cues. In addition or as an alternative, it is also possible to determine and signal the limited functionality of an electrical system; and this electrical system, to which a plurality of electrical consumers are assigned, may be, for example, a steering system. The limited functionality of the electrical consumer can be signaled by way of an output unit that is designed to lend itself, for example, as a display such as an LED display. This arrangement allows the vehicle user to obtain in an advantageous way information as to which electrical consumer and/or which electrical system is or are capable of functioning now only to a limited extent.
According to another advantageous embodiment, an additional and/or reduced energy consumption is determined in comparison to an energy consumption, when the maximum released power, which the electrical consumer of the motor vehicle may consume, is determined as a function of at least one predefined target weighting value. The additional and/or reduced energy consumption is signaled by use of visual cues and/or auditory cues. This strategy allows the vehicle user to obtain in an advantageous way information about the energy consumption, as a function of one or more specific weighting value(s), and to use this information to make a decision about whether he would like to maintain the specific weighting value(s). The additional and/or reduced energy consumption can be signaled by use of an output unit that is designed to lend itself, for example, as a display such as an LED display.
According to an additional advantageous embodiment, the input is performed via an input unit, which has a control panel that is designed as a sensor screen and that has a geometric shape with a plurality of corners, wherein a number of corners is equal to a number of weighting values. This arrangement supports an intuitive input in an advantageous way. In the case that the aim is to perform an input for less than three weighting values, the control panel can be configured in a manner analogous to a bar graph.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.